• Introductions and Setup (~15 min)
• Mini-lecture: What Can Drones Do? (~30 min)
• Interactive: Study Design (~30 min)
• Interactive: Data Collection / Flight Demo (~30 min)
• Mini-lecture: Photogrammetry Concepts (10 min)
• Interactive: Data Processing Lab Part 1 (20 min)
• Mini-lecture: Ground-control Points (5 min)
• Interactive: Data Processing Lab Part 2 (20 min)
• Mini-lecture: Regulations and Safety (10 min)
• Interactive: Data Processing Lab Part 3 (10 min)
• Mini-lecture: Data Management and Computing (10 min)

• About me
• About you guys

Photogrammetry Software: [http://www.agisoft.com/downloads/installer/]

GIS Software: [https://qgis.org/en/site/forusers/download.html]

Data: [http://tinyplant.org/RMBL_2018_UAV_data.zip]

Presentation: [http://tinyplant.org/RMBL_2018_UAV_slides.html]

• Scaling from plots to landscapes
• Bridging the gap between field measurements and sattelite remote-sensing
• Seeing the invisible: Beyond visible wavelengths
• Counting the uncountable: Computer vision
• The technology is getting (relatively) cheap and robust

• Multicopters: Stable, Slow, Manuverable, VTOL

• Fixed wing: Fast, Long-ranging

Multicopters:

 - Pro-sumer (<$2000, payload < 200g, 20 - 30 min flight time). 
    e.g. DJI Phantom 4
    
 - Professional (>$4000, payload < 3kg, 30 - 45 min flight time): 
    e.g. DJI M600

Fixed-wing

- Pro-sumer (<$2000, payload < 100g, 30 min flight time): 
    e.g. MapIR Magpy
    
- Professional (>$6000, payload < 1kg, 60 min flight time): 
    e.g. Aeromapper Talon, Firefly6 Pro
    

• Stabilized RGB Cameras: DJI Zenmuse (Built-in)
• Modified RGB/NIR Cameras: MapIR Survey 3 (80g, ~$500)
• True Multispectral Cameras: Parrot Sequoia+ (~100g, ~$3000)
• Thermal Imaging: FLIR Duo Pro R (~100g, ~$4000)
• Hyperspectral Imaging: Headwall Nano-hyperspec (~300g, ~$8000)

• LiDAR - Phoenix miniRANGER (2.5kg, ~$10,000)
• L-Band Radar (Soil Moisture): Black Swift Technologies (?,?)

Sampling the Landscape: Three general designs

Survey Area - f(Ground Resolution, Sensor, Flight Time)

Quadcopter DJI Phantom 4 Pro (20 Mpix RGB Camera):

• 2 mm ground resolution, 10m height: ~1 ha per flight

• 3cm ground resolution, 120m height: ~40 ha per flight

Fixed-wing Firefly6 Pro (40 Mpix RGB Camera):

• 3cm ground resolution, 120m height ~200 ha per flight

• Maintain Visual Line-of-sight: DJI Phantom - ~500m

• Max altitude: 400 feet (~120m) AGL

Brainstorm a study design (10 min)

Then share and refine it with a team of two (10 min)

• What are the scientific questions?

• What measurements are necessary?

• What UAV-based sensors might you use?

• What ground resolution do you need?

• Survey design: Wall-to-wall? Plots? Transects?

• Platform Type: Quadcopter? Fixed-wing?

• What would be the overall hardware cost?

Goal: Build a 3D model of the Townsite.

Requirements:

• ~3cm ground resolution

• 66% overlap between images

• R Script Demo

• Litchi Mission Hub Demo

Meet behind the Natural History Building in 5 minutes.

Photogrammetry - Making (correct) Measurements from Photographs

Undistorting photos to get a true “top-down view”

Orthorectified Photo = Orthophoto

Reconstructing 3D Scenes from collections of 2D Images

Under the hood: https://en.wikipedia.org/wiki/Scale-invariant_feature_transform

##Photogrammetry Software

• Proprietary: Agisoft Photoscan, Pix4D

• Open-source: Regard3D

• Cloud-based processing: DroneDeploy

• GIS Software: QGIS, ArcGIS

• Patented algorithms for components of SfM

• Good interfaces for 3D modeling are hard to build.

• Agisoft Photoscan - Fast, Stable, Easy to Use, Relatively Cheap

Follow the preparation steps (up to Stage 1) in the tutorial from NCSU

Add photos from the data folder using Workflow -> Add Photos…

Follow the steps in Stage 1 of the tutorial from NCSU in order to Align the Photos.

• Located in the field with a high-accuracy GPS.
• Improves geometric accuracy of resulting maps.
• At least 3, ideally 7 - 10 per flight

Follow the steps in Stage 2 of the tutorial from NCSU in order to locate the GCPs in photos.

Then follow the steps in stage three through the step Menu > Workflow > Build Dense Cloud. This will take a while to process.

Federal Aviation Administration (FAA) considers drones to be aircraft

• Flying for research: considered commercial use, requires remote pilot certification

Key Regulations

• Airspace restrictions - near Airports & Military Bases

• Temporary flight restrictions - Air Force One, Fire Fighting, etc.

• Line-of-sight, visibility, and wind requirements.

• NPS - No drones at all except in a few parks

• USFS, BLM - Must get a special use permit

• Designated Wilderness - No drones

• State Parks - Varies by state and park.

• 10m from roads, trails and people

• Comply with FAA regulations

• Minimize conflict with other researchers

• Coordinate with science director Jennie Riethel

Follow the steps in Stage 3 of the tutorial from NCSU in order to build the 3D Mesh and Texture.

• Programmed Flights - avoid trees by >4m, pay attention to overhead wires

• Low-elevation flights (<20m) - ground-following flights using a high-res DEM

• Private property - DroneHunter, Assumption of Surveillance

• Be conspicuous and friendly, take time to explain the purpose of the flights

• GPU vs CPU Performance

• 300 minutes of flight time / week = 120GB / Week of Imagery

• Processing in the cloud - Paperspace virtual servers.

Did we cover everything?

NC State UAV course